ultrix man page for sqrt

sqrt(3m)																  sqrt(3m)

Name
       cbrt, sqrt - cube root, square root

Syntax
       #include <math.h>

       double cbrt(x)
       double x;

       double sqrt(x)
       double x;

       float fsqrt(float x)
       float x;

Description
       The function returns the cube root of x.

       The and functions return the square root of x for double and float data types respectively.

   Error Due to Roundoff and Other Reasons
       The function is accurate to within 0.7 ulps.

       The function on this machine conforms to IEEE 754 and is correctly rounded in accordance with the rounding mode in force; the error is less
       than half an ulp in the default mode (round-to-nearest).  An ulp is one Unit in the Last Place carried.

Diagnostics
       The function returns the default quiet NaN when x is negative indicating the invalid operation.

See Also
       math(3m)

								       RISC								  sqrt(3m)